One of the reasons we look for or send spacecraft to objects like Trojan asteroids is that they provide us with primitive samples of the early solar system. Almost everything in our solar system is about 4.6 billion years old since the Sun formed and the leftover gas and dust became a protoplanetary disk that spawned all our worlds and rocks and such. And from our observations of other planetary systems, we thought they were much the same. Until now.

In new research published in Astronomy & Astrophysics, scientists describe how a binary star system, where one star is dying and throwing out gas and dust, may have a baby planet forming from that material. First author Jacques Kluska explains: In ten percent of the evolved binary stars with discs we studied, we see a large cavity in the disc. This is an indication that something is floating around there that has collected all matter in the area of the cavity.

And that cleanup could be the work of a new planet. The researchers found more evidence for this possibility when they analyzed the surface of the dying white dwarf. Kluska goes on to explain: In the evolved binary stars with a large cavity in the disc, we saw that heavy elements such as iron were very scarce on the surface of the dying star. This observation leads one to suspect that dust particles rich in these elements were trapped by a planet.

What’s really interesting is that this work wasn’t about one star system; it was about 85 binary star systems. The team combed through existing observations of those 85 star systems and found that ten binary pairs showed evidence of gaps with new planets forming. Planets gonna planet, I guess.

More Information

KU Leuven press release

“A population of transition disks around evolved stars: Fingerprints of planets,” J. Kluska et al., 2022 February 1, Astronomy & Astrophysics